Sunday's programme was one of the most searching ever attempted by the intrepid Birmingham Philharmonic Orchestra, and its success was brilliantly achieved.
Michael Lloyd, a conductor of remarkable versatility, musicianship glowing from whatever score he touches, inspired his players as much in the languid subtleties of Delius as in the mighty, obsessively detailed paragraphs of Mahler.
Two Delius miniatures, (On Hearing the First Cuckoo in Spring and Summer Night on the River) found Lloyd sculpting wonderfully cushioned string chords, though the woodwind solos above them could have been delivered with more personality.
But both pieces cast a mesmeric spell, settling the audience for the huge concentration they dedicated to a moving account of Mahler's valedictory Ninth Symphony.
From the outset Lloyd let us understand that this was to be a fluid, supple journey towards a painfully-won Nirvana, unfolding the huge edifice naturally and with telling punctuation of important structural events.
Even these amazing amateur players were occasionally caught out by the demands of Mahler's scoring, but there were too many tremendous moments in this meticulously, patiently rehearsed performance for us to pay heed to the downsides.
Trumpet and horn principals were outstanding, as secure and expressive as any you could hear in our great professional orchestras. Beneath them were full-throated strings, beautifully balanced by Lloyd in the many inwardly-groping passages where Mahler tries to subdue his Freudian daemons - and there are plenty of those in the death-grinningly vicious inner movements, woodwinds flickering and sauntering devilishly.
The long, regretful farewell was lovingly sculpted, followed by an audience silence more eloquent than the thunderous applause which eventually erupted.